A transistor is an electronic device that permits current flow in electronic circuits. In this regard, the transistor permits the current to flow in a controlled manner whenever an electronic circuit attempts to push current through the transistor. In this manner, the transistor generically operates as a regulator or valve, which regulates the flow of current.
In order to mitigate the effects of impairments such as noise, transistors may be arranged so that they form a differential amplifier. Differential amplifiers form the basis of operational amplifiers, the latter of which are generally referred to as op amps. Differential amplifiers are electronic circuits, which are designed with an internal symmetry that is configured to cancel errors that are shared by both sides of the differential amplifier. These errors may include internal or external errors. Internal errors may include temperature changes, which in certain instances may affect both sides of the operational amplifier to approximately the same degree. Transistor mismatch is another example of an internal error. Whenever both sides are affected to approximately the same degree, a nulling or canceling effect occurs. External errors may include noise picked up by inputs of the differential amplifier. In this regard, the differential amplifier may be adapted to eliminate common mode noise. Furthermore, the differential amplifier may require that the signal appear as a difference between waveforms occurring on either side of the differential amplifier. Accordingly, the differential amplifier may be configured to reject certain signal components such as noise and amplify desired signal components.
Some conventional differential amplifiers require a reference voltage or reference current in order for the differential amplifier to operate properly. Additionally, some differential amplifier designs utilize large numbers of transistors. In general, the greater the number of transistor devices, the greater the number of operating variables that will vary with respect to each of the sides of a differential amplifier. Consequently, differential amplifiers that utilize a large number of transistors may be more difficult to control and tune, and may also be less predictable with respect to process or operating variations. Furthermore, most conventional analog differential amplifiers are generally adapted to take a relatively small differential input voltage and produce as an output a voltage having a larger magnitude. These conventional analog differential amplifiers are usually optimized to operate in a specified voltage range and may not function at all if operated outside that range.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with some aspects of the present invention as set forth in the remainder of the present application with reference to the drawings.